Achieving High Accuracy with a GNSS Surveyor
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The Bad Elf GNSS Surveyor is capable of achieving positional accuracies of one meter or less when setup and configured properly. This tutorial is a guide to ensuring you have the correct configuration for the GNSS Surveyor. Examples are included that show real-world troubleshooting. Completing this checklist provides you the knowledge of how to verify your GNSS Surveyor is configured to maximize accuracy.
In this section we take you through the steps of how to use the Bad Elf iOS application to verify your receiver is properly configured. During this process, we will ensure that your GNSS Surveyor is configured properly to use SBAS and PPP (Precise Point Positioning).
In this section we confirm that the settings changes have taken effect properly. Below are side-by-side examples, from the field, that demonstrate less than optimal and optimal configurations. Explanation is provided such that you can quickly assess when your GNSS Surveyor is performing optimally.
Using the GPS button on the bottom left of the GNSS Surveyor, cycle through the menus until you reach a menu that has “Fix Type” in the upper left corner.
In this case only a 3D solution is provided. This Fix Type indicates that SBAS satellites may not have been acquired yet and as such the GNSS Surveyor is not achieving maximum accuracy.
The Fix Type indicates WAAS+PPP which means the GNSS Surveyor is configured properly, is receiving SBAS, and PPP is active. Leaving the device stationary and unobstructed will further help maximize accuracy.
The Bad Elf app has a satellite screen that shows the accuracy measures, location of satellites, and satellite acquisition state.
In this case only a 3D solution is provided. This Fix Type indicates that SBAS satellites are in acquisition mode may not have been acquired yet and as such the GNSS Surveyor can’t achieve maximum accuracy.
Note: this example is applicable to North America. Typically one will see the last three SBAS satellites on the right of the signal strength bars
The Fix Type indicates that the GNSS Surveyor has acquired a lock on all three SBAS satellites and therefore can improve its accuracy with these corrections.Only one of the three is required; although it doesn’t hurt to have two or more.
Now that SBAS is acquired, the GNSS Surveyor will being using PPP to improve the stationary position of the receiver.